1. Field of the Invention
This invention generally relates to tilt-up wall construction, and more specifically to a system to create openings in a tilt-up wall.
2. The Relevant Technology
Concrete structures are routinely poured all over the world. These structures can include poured walls or solid, secured bases in which to build walls or other structures. In the United States, the walls of large commercial buildings are usually constructed using a tilt-up method. In such an approach, concrete walls or wall sections are formed on substantially flat, hard surfaces, such as a concrete floor of the building under construction. This surface is usually prepared with a suitable, bond-breaker material to prevent the newly formed wall or wall section from adhering to the floor.
Typically, forming the walls or wall sections requires a number of wood planks, such as two-by-eights, or the like, to define an area to receive concrete. The wood planks define the edges of the final wall or wall section. To provide smooth, beveled edges to the finished concrete wall or wall section, chamfers are often created by attaching triangular wood pieces to the form or wood planks. This is extremely labor intensive due to the difficulty involved in cutting the wood pieces and then nailing them to the wood planks.
A similar technique is used to create holes in the tilt-up wall to receive a window. For instance, a number of wood planks are mitered and then nailed together to create a form that defines the space within which a window will be placed at a later date. As with the wood planks forming the outer peripheral edge of the concrete wall, chamfers have to be attached to the window wooden planks in a similarly labor intensive manner.
Once the triangular pieces are attached to the window form and the general form for the wall, these forms are attached to the floor, so as to prevent dislocation or movement, particularly in a lateral direction. Once the forms have been arranged to create the defined area, the concrete mix is poured into the space. After curing and hardening the newly poured concrete, the wooden forms are removed and the concrete wall section is lifted from the floor by a crane or other suitable device to complete a wall section of the building.
During removal of the wooden forms, the planks and those triangular pieces used to form chamfers can be damaged. At least the triangular pieces, and more often both the wooden planks and the triangular pieces are damaged and must be discarded. For instance, cracking and splintering of the wood can occur, thus making the form unusable for creating new walls or wall sections. This not only wastes material, but can be a safety hazard because splintered wood can cause injury.
Different techniques have been employed to reduce the difficulty of creating the chamfers for the finished wall or wall section. In one attempt, an elongated base is used to support the wood plank and form the chamfer. The base includes a chamfered portion and a channel that receives the wood plank. Unfortunately, because the wood planks and the base have predetermined lengths, it is necessary to cut both the wood plank and the base to create the desired area to receive the concrete. This undesirably increases the time and costs required to construct the wall or wall sections. Further, the channel within which the wood plank mounts may become damaged, and thus incompletely receive the wood plank. Additionally, the wood plank may rest within the channel at an undesirable angle or orientation with respect to the surface upon which the wall or wall section will be formed. This can result in walls or wall sections having angled ends that cause adjacent walls or wall sections to abut incorrectly.